#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>

using namespace std;

class Solution {
public:
    int takeAttendance(vector<int>& records) {
        int left = 0;
        int right = records.size() - 1;
        while (left < right)
        {
            int mid = left + (right - left) / 2;
            if (records[mid] == mid)
            {
                left = mid + 1;
            }
            else
            {
                right = mid;
            }
        }
        return left == records[left] ? left + 1 : left;
    }
};

int main()
{

	return 0;
}